This invention relates to video display processor systems for display of video data or information on a single display screen of a raster scan type video display and more particularly to simultaneously displaying video data reflecting the operation of two processors in discrete portions of a single display screen and the user interface therefor. Such a multiprocessor system may comprise a first display processor, e.g. a host computer system, having a display capability for simultaneously displaying both the video data of the first processor and the video data of at least one other display processor, which may, for example, be the emulated display processor of target system central processor, e.g. the IBM PC, which other display processor is connected to the host computer. The host computer system allocates a portion of its display screen for emulation of the display screen environment of the emulated display processor. Since the early 1970's, the development and advancement of raster scan display systems for displaying video information on a video or CRT display has progressed at a fairly rapid pace. Examples paramount in the advancement of this area of art include, inter alia, the use of bitmaps which are memory representations of the pattern of information to be presented on the display screen of the video display, the bitblt or raster op routine which is a fundamental bitmap operation for the bit block transfer of a memory block of information in the display memory from one location to another location in that memory, and the division of a bitmap display into several regions, also referred to in the art by many other terms such as viewports, files, ports, windows, pages or layered bitmaps, to provide separate display of video information in independent screen regions. The processor systems controlling such multi-region screens may include, for example, means (1) for the manipulation of displayed data presented or present in the different regions of the display screen, (2) for the relocation of either entire regions including the displayed data therein to other portions of the display screen or beneath or on top of other display regions of the display screen and (3) for the relocation of displayed data in one screen region to another screen region. Examples of such systems are the Xerox 8010 Professional Workstation or Information System first commercially introduced by Xerox Corporation in April, 1981 and the Xerox 1100 SIP for the Xerox Smalltalk-80.TM. System first commercially introduced in November, 1983 and previously described with pictorial representations in Volume 6(8) of BYTE of August, 1981, published by BYTE Publications, Inc., a subsidiary of McGraw-Hill, Inc. See also U.S. Pat. No. 4,414,628 which discloses a raster display system for processing and displaying a plurality of superimposed pages on a single display screen. Further, U.S. Pat. Nos. 4,533,910, 4,450,442 and 4,555,775 respectively disclose raster display systems for (1) creating and displaying video information in different regions on a single display screen, (2) displaying a plurality of display files from separate processors in superimposed relationship and in any desired combination thereof on a single display screen and (3) displaying several superimposed bitmap layers, each representative, for example, of a window port, and wherein all layers are displayed, as superimposed, and are running simultaneously so that any one of the windows may be interacted with at any time.
In recent times, with the introduction of the microprocessor-based IBM PC and its more recent follow-ons, such as, the IBM PC XT and the IBM AT (all collectively hereinafter referred to as the "IBM PC") produced by the IBM Corporation and with its high level of placement in the business community and general consumer market, there has been a number of manufacturers and developers developing systems that have been either designed to be an equivalent to an IBM PC or designed to emulate an IBM PC via an emulating software environment. The wide acceptance of the IBM PC has also created a hugh software industry catering to the IBM PC market, including emulated or equivalent versions in that market, for various kinds of applications, e.g. Lotus 1-2-3.TM., Wordstar.TM., Multimate.TM., Symphony.TM., Framework II.TM., Multiplan.TM., Turbo Pascal.TM., C Complier (Microsoft.TM.), Pascal Complier (Microsoft.TM.) and Cobol Complier (Microsoft.TM.), etc. Manufacturers and developers have found that in order to maintain their own personal computer based system viable in the market place, they must also make some provision for running IBM PC applications and programs since many customers or potential customers already have IBM PC equipment in use in day to day business and work.
For the most part, these competing manufacturers and developers have provided in their systems separate hardware and/or software for emulating the IBM PC which may be booted and run separately, while their own proprietary system is inactivated, to permit the running of IBM PC applications and programs already in the hands of IBM PC users. While users of such competitive systems can process data or run applications or programs applicable to either the proprietary system or to the IBM PC emulated or equivalent system provided in the same machine, there has been no offering of a means by which the proprietary system can be running simultaneously on the same display facility with the IBM PC emulated or equivalent system so that IBM PC applications and programming could be carried out while the proprietary system is also concurrently running and to further permit the transfer of displayed video data and/or application and program files from one such system to the other for further use or processing.